Habby p



Jan. 24, 1928.

H. F. SMlTH NATURAL GAS DILUTION S'YSTEM Filed April 27, 1922 Patented Jan. 24, 1928.

UNITED STATES 1,651,045 PATENT OFFICE.

HARRY F. SMITH, OF DAYTON, OHIO, ASSIGNOR TO THE GAS RESEARCH COMPANY, F DAYTON, OHIO, A CORPORATION 0F OHIO.

NATURAL-GAS-DILUTION SYSTEM.

Application led April 27, 1922. Serial No. 556,854.

This invention relates to a gas supplying system for supplying a combustible gas, consisting of a gas of higher heat value, such as natural gas, in admixture with a combustible gas ot lower heat value.

One of the objects of the invention is t'o provide a method of admixing two gases, or other fluids, of varying characteristics and supplying them to a deliverymain for transmission to any desired place of use or storage.

Another object of the invention is to provide a method of diluting natural gas with another combustible gas of lowerheatvalue.

Another object of the invention is to pro-r vide a method of diluting natural gas with a comparativelv low heat value gas, such as producer gas. the pressure ofthe natural gas being utilized for causing the generation of the producer gas, for causing the admixture of the natural gas and producer gas, and`for supplying the resultingmixtureat any desired pressure to the delivery main, or place of use.

Still another object of the invention 1s to provide suitable apparatus for carrymg out this method.

Other objects and advantages will be apparent from the description thereof set out below when taken in connection with the accompanying drawing.

The apparatus for carrying out this method is illustrated diagrammatically in the drawing. in which some of the parts are shown in vertical section in order to more clearly disclose the invention.

As is welleknown the supply of natural gas available for domestic and industrial use, in this country, has been failing rapidlydur in cr the last few years. In addition to they evident failing of the supply, the demand has increased tremendously, so that every lay there is a wider lgap between production and demand. Under these circumstances the gas companies, particularly in winter, have difficulty in supplying even the domestic consumer; the industrial consumers in mostl cases being entirely deprived of natural gas during the winter months. In some places this condition has been somewhat relieved by diluting`` the natural gas with artificially prepared gas. such as producer gas, Naturally the resulting gas has -a lower heat value than the natural gas itself, but by varying the proportions ot natural gas and producer gas any desired B. t. u. may be secured. t

In this invention the pressure of the natural gas as itA comes from the Wells, which pressure 1s often in excess of tive hundred ounds and is seldom less Athan two or three undred pounds per square inch, is utilized for driving the pump or exhauster which operates the producer, the natural gas being expanded to a lower pressure, and the pro# ducer gas being compressed to a higher pressure during thisv operation. Furthermore the natural gas as it is expanded to do work has its temperature very much lowered, the temperature reached being dependent upon operating conditions, but under general operatlng conditions reaching a temperature of 0o Fahr. or' lower and this cooled gas may then be used in the cooling of the producer gas, which is at a very high temperature as it leaves the generating chamber of the producer but which is subjected to a coolmg action before it is brought into heat interchanging relation with the natural gas. The producer gas during this cooling is itself brought to a comparatively low temperature, about 32 Fahr., and, being at` the same time under substantial pressure, is passed through water where the carbon dioxide contained in the gas is absorbed, the result being an increase in the heat value of the gas and also the generation of a valuable byproduct, namely carbonated water. I

As shown in the drawing, natural gas under Well pressure, is introduced through the pipe 10, which opens into the valve chest 11, of the engine cylinder 12. This cylinder is substantially identical in construction with an ordinary steam engine cylinder, and the entire engine is shown conventionally, and somewhat diagrammatically, since any suitable type of pressure operated motor will function satisfactorily. two passages 13 and 14:, cachot which is connected at one end, tothe interior of the steam chest and. at the'other end, to'one end of the interior of thev engine cylinder. 100

These two passages are controlled by means of a` conventional D type distributor valve 15. the construction being such that as the valve 15 is properly moved within the valve chest. pressure gas from the pipe 1() will 105 be admitted first to one end of the cylinder and then to the other to cause rec-iprocation of the piston 16 and the piston rod 17 attached thereto. Arranged substantially midway of the cylinder is an outlet or exhaust 110 l5 The cylinder has an outlet ort or passage 2O openino' thereinto, to wiich is connected the outlet pipe 21. The distributor valve has connected thereto suitable actuating mechanism desi nated generallly bythe numeral 22, wh1ch 1s also operative y connected to the iston rod 17, the construction beingsuch t at as the piston and the piston rod carried thereby reciprocate, during operation of the englne,

. suitable sliding of the distributor valve will be secured to properly control the flow of pressure gas to, and the exhaust of the expanded gas from, the cylinder 12.

the cy nder 12 is a pump cylinder 30, which is coaxial with the cylinder 12, the piston rod 17 extending into the cylinder 30 and being connected to the piston 3l, within that pump cylinder. As the piston 16 reciprocates within the cylinder l2, under the expanding action of the natural gas, the piston 31 will-be caused to 4correspondingly reciprocate within the cylinder 30. The cylinder 30 is provided with an inlet port, controlled by a suitable inlet valve 32, and with an outlet port, controlled by a suitable outlet valve 33, the two valves 32 and 33 being shown as conventional disc valves.

The pump 30, during operation functions as the pump or exhauster for causing operation of a suitable as producer, by blasting the fuel bed therein, and for forcing the generated producer gas under suitable pressure through proper treating apparatus and then into the natural gas for admixture therewith. Any desired type of producer may be used, but asuction producer is quite satisfactory, and aproducer of this type is therefore illustrated diagrammatically herein. This producer is designated generally by the numeral and details of construction thereof are not included-inasmuch `as `the specific construction 'of the producer is acter of the gases generated from these vari-f ous fuels in the producer is, generally', the same. But where lignite or bituminous coal is used the gases must be .subjected to suit,4

able cleaning action to remove the tar which is producd during the gas generatlon, whereas with an anthracite or colte producer the ges may be.szenerallv. suicieutlvcleaned air and moisture for the gas making reac- Cooperatively positioned with respect toA chamber of th'e producer, where it is spray by passing it through an ordinary sawdust scrubber. So far as this method of dilution is concerned, however, it is a matter of indifference what character of fuel is used in the generation of the gas so long as the pro ducer gas itself is of suitable character. By Way of illustration, however, the producr is shown as one adapted to generate gas from soft coal, since this is a more generally available fuel than anthracite, and consequently suitable cleaning apparatus for removing the tar during the generation of said gas is illustrated.

The producer being suction operated, the

tions is drawn through the producer underthe suction action of the pump 30 the generated gas passing olf through the `oftake pipe or downcomer 41 into the bottom offa cooler or condenser 42. This condenser may be of any conventional type, such for instance as a cylindrical shell having a pluy rality of bales therein, water being sprayed into the upper end of the shell to trickle down over ythese ballles and thus come into intimate contact with the gas as it passes upwardly through the condenser, the gas being thus cooled and at the same time washed l'y the water with which it comes in contact.

he lgas, after washing and cooling, passes from the upper end of the condenser through the pipe 43 to a tar separator or extractor illustrated diagrammatically at 44. Any suitable type of tar extractor ma be used, but the form shown herein is that 1llustrated and described in the patents to Harry F. Smith No. 1,099,773, dated June 9, 1914. and 1.140,198, dated May 18, 1915. In this type of extractor or separator the tar is not actually removed from the gas within the separator'itself, but it is so acted upon that it 1s caused to agglomerate into large drops which willv fall out of the gas under the action of gravity after they pass out of the separator. In order-to accomplish this phase of the cleaning the gas after it leaves the separator passes through the fitting 45, Within the delivery lll lill

)Ill

ipe 46, which has a baille therein which he ps to throw down the drops of tar contained inthe gas. Connected to vthe fitting 45 is a tar tank or sump 47 into which the separated tar drains. Preferablv the tar 1s removed from this sump through the pipe V48,'and returned to the generating overthe topof the fuel bed and assists the gas making reactions. This method tar return is shown in the patent to Harry .F. Smith- No. 1.394,043 dated October 18 '1921. Of ourselthis method of tar return .is not in anyway anessential feature of this,

particular invention, itbeing only desirable that a suitable producer gas be generated and fed through the pipe 46 to the inlet port of 1th,., vlinder an A: the producer nas passes llo inder 12, an

through the pump 30 it is suitably compressed and delivered through Vthe outlet valve of that pum into the pipe 50. The pressure to which tie producer gas is raised y means of the pump 30 is considerably belowthe pressure of the natural gas within the pipe 10, but the construction and arrangement of the natural gas motor and of the pump 30 is such that when the natural gas and the' producer as are fed into the deliver. main, they wi lv be under substantially t e same pressure. In actual practice the natural (gas 1s expanded, within the cylthe producer gas is compressed within the cylinder 30, :so that when finally admixed these two gases will have a pressure of about 30 pounds per square inch. This pressure is not in any way essential, but it as been found quite satisfactory. Any other desired 'pressure may be "used, and by properly constructing and arranging the natural gasy engineand the producer gas pump the natural gas can be expanded down to any desired pressure and the producer gas compressed tola corresponding pressure. The compressed producer gas, which is at a temperature considerably above atmospheric temperatures, is passed into a heat interchanger or cooler 51, which may be of any suitable form, but which, as shown diagrammatically, has somewhat the saine construction as a fire tube boiler, the'warrn or hot producer gas assing through the tubes 52, and a cooling uid, such as water, which is introduced through the pipe 53 passing upwardly over those tubes to cool thegas in them and then out through the pipe 54. The warm water passing from this cooler through the pipe 54 is introduced into the upper end of a cooling tower 60, which also may be of any suitable form, but which is illustrated diagrammatically as a cylindrical shell provided with wooden slatsy or blocks 61 therein so arranged that the water introduced through the pipe 54 will spread out in thin sheets over the surface of these blocks andthus be more readily aerated and cooled bythe air. whichrpasses in through the openings 62 in'the-.bottomof the cooling tower. 'Thefcoolcd 'producer gas, still under pressure, passes fromfthe cooler 51 through the pipe l65,vY-hich opens'into another cooler 66,

.whichisfsubstantially identical in construe-f tion with the coolery 51 described above. But" `in this coolerg66 the; natural gas 'from pipe 21 passesthrough lthe tubes'67, v`and thence out throughthe pipe 68, while Athe producer Vgas @from ,the theV shell66-and aroun natural` asin the pipe 21,'a er expansion withinA t quite low temperature, the temperature'pe ing dependent upon the amount of capiI sion. v resuming a .well Dressureof some 200 the fables through 'thev water` within` the.y absorb-f ipe65 Y, passes .into l lover. the, tubes .6'75- and thence out through` the Aipe '69.1???The`4 e cylinder 12 to do work, israta pounds, and an expansion to about 30 pounds per square inch, this temperature will probably be in the neighborhood of 0 Fahr. The producer gas going from the cooler 51 will be at a considerably higher temperature probably around atmos heric temperature, say 60 to "i0o Fahr. s the two gases pass through the cooler 66, the natural gas will have its temperature raised and the producer gas will have its tempera ture lowered: The resulting temperature of the natural gas and the producer gas, as these two gases leave the cooler 66 will be dependent upon the relative quantities of the two gases passing through the cooler, the relative temperatures of the two gases as they ass into the cooler, and the relative speci c heat of thetwo gases. The relative 4proportions of producer gas and natural gas will be entirely dependent upon the amount of dilution that is desired.- Of course the greater the proportion of producer gas that is introduced the lower the heat value, for while natural gas will average around 1000 to 1100 B. t. u. per cubic foot, producer gas will range around 140 to 180 B. t. u'. per cubic foot. Obviously lthe greater the proportion of producer gas the lower the heat value. It has been found, however, that with admixture of subtantially 40% producer gas and 60% natural gas practically the same results can be secured in use as are secured with undiluted natural gas. With the two gases in substantially this proportion, and with the temperature of the natural gas entering the cooler 66 at substantially0 Fahr. andthe temperature of the producer gas entering that cooler at substantially 60 Fahr, the prol A ducer gas will be cooled to around 30 to 32"v Fahr. without any correspondingly great rise in the temperatureof the natural gas.

This is due to the fact that the specific heatof natural gas is substantially twice the specic heat of producer gas.

The natural gas after passing from the cooler 66 through the pipe 68 is led into a delivery main 70, which leads to any desired place of use or storage. The-producer gas passes ofi' through the pipe 69 which opens into an absorbing tank 75. .This l tank con-A tains some` absorbing mediu1n,l preferably water ata temperature about -reezin'g., The gasjroznf 4the pipej69 is 4kbroken up into line f streamsby means ofthe nozzle 7 6,and bubfig tank '75; The gas-and waterwithin the v.lbaorbing -1 "1,5" being findenv afl pressure vinfefxcess5pti rone atmosphere, sayf30 pounds per square" 'nch, andatQateinperature substantially flfezing;

'the-1 water" has' a'capacity .f

" zfor.absorbinglconsiderableyguantities of car i bondioxidef-Andas'there will `bein` prac -v tice aubstantialquantities" of carbon dioxide. su.

len percent, it will be absorbed by the wa ter within the tank 75. This results in in creasing the heat value of the producer vas as it is finally delivered and admixed wlth the natural gas. Furthermore it oil'ers a means of obtaining a valuable by-product since carbonated water is secured within the t-ank 5. As shown the apparatus is so constructed that the water from the tank 75 is passed through the pipe 53 into the cooler 51, a suitable pump 7T being located within the pipe for feeding the water from the tank To to the cooler. And inasmuch as the water trom the cooler 51 passes into the cooling tower (30 where the pressure upon it is removed, while it is at temperatures in excess of atmospheric temperatures, the carbon dioxide previously absorbed therein will escape into the atmosphere. Of course if desired the cooling tower could be entirely dispensed with and water fed through the cooler 51 from some outside source, so that the carbonated water from the tank 75 could be utilized as a by-product. In the construction shown, in which this carbonated water is not utilized as a byproduct, but is recirculated through the heat interchangers or coolers, the aerated water from the cooling towel' 60 passes downwardly through the pipe 8l) into the heat interchangcr 8l which is substantially identical in construction with those heretofore described the water passing around the tubes 82, and thence throuffh the pipe 83 into the absorbing tank 75, wliile the producer gas with its carbon dioxide removed, passes through the pipe 84, where, as it moves through the tubes 82, it is heated by the water surrounding those tubes, this water being it is to be remembered, at about atmospheric temperature While the gas coming from the absorber 75 is at a temperature close to freezing. The producer gas leaves the heat interchanger 8l through the pi e 85, which opens into the delivery main i0, the gas within this main being admixed with the natural gas delivered through that tube to the pipe 68. If desired the natural gas and producer gas may be fed into a mixing chamber before being fed into the delivery main but in practice sufficiently intimate admixture of the two gases is secured in the delivery mam.

As set out above the natural gas is so expanded within the cylinder 12 and the producer gas is so compressed within the pump 30 that they are finally delivered into the main 70 under substantially the same pressure, 'and satisfactory results will be obtained if this pressure is approximately 30 pounds per square inch.

As the water passes through the heat interchanger 81, not only is the producer as warmed up, but the water is in turn coo ed down, so that the water passing therethrough to the absorbing tank will be at a temperature considerably below atmospheric temperatures, and consequently within the absorbing tank T5 that water, as the cold producer gas bubbles through it will have this temperature still further lowered so that conditions within the absorbing tank are such as to facilitate the ready absorption of the carbon dioxide.

'.lhe cooling tower should be so positioned with respect to the heat interchangcr 8l that sulliricnt heat is provided to give a pressure within that heat interchanger and the absorbing tank at least equal to the pressure ol the gas within the absorbing tank. Ur a pump should be provided Al'or delivering thiswater under the desired pressure.

lt should be also borne in mind that with some types ol coal certain undesirable impurities are obtained in the gas which are not removed in the conventional purifying apparatus. For example where a coal is high in sulphur it is not unusual to get such quantities of hydrogen sulphide or sulphur dioxide in the gas that it would be unpleasant for domestic use. 'lhese impurities are also, however, subject to absorption in water at a low temperature under pressure, and cousequently where such sulphur compounds are in the gas they will also be removed within the absorption tank 75. Of course where these impurities are present within the gas and are absorbed Within the tank the carbonated water could probably not be used without some treatment. Under these conditions, however, recirculation of the water loo from the absorbine tank through the cool ing tower would e in no way interfered with since the sulphur compounds would escape 1nto the atmosphere within the ab- .srbmg tower just as does the carbon diox- 1 e.

It is sometimes found desirable to have more than one absorbing tank. This may be desirable either because one tank does not remove all of the carbon dioxide, sulphur lmpurities and the like, or because the gas contains certain impurities which would notbe removed by the water within the tank 75 but might be easily removed by passing them through some other material. Obviously as many absorbing tanks may bc used as circumstances require.

It' for any reason the expansion of the natural gas does not liberate enough energy. to satlsfaetorily operate the pump 30, then added means may be provided. In' the form ot apparatus shown, for example, a gas engine, adapted to operate on the admixed gases, may be used as a supplementary power source. Any other form of supplementary power source may be used as desired.

lso it is not at all essential that a reciprocating gas engine be used, for a turbine might be used in place thereof.

While the method herein described, and the form of apparatus for carrying this method into effect, constitutes preferred embodiments of the invention, it is to be understood that the invention is not limited to this precise method and form of apparatus, and that changes may be madein either Without departing from the' scope of the invention which is defined in the appended claims.

What is claimed is:

1. The method in the dilution of natural gas with a low Value heat gas, such as producer gas, the natural gas being under higher pressure than the producer gas, in which the natural gas is expanded within an engine to cause operation of a blasting pump connected with a producer gas generator, with resultant loweringof the temperature of the expanding natural gas, and withdrawal of the generated producer gas from the producer and delivery of this producer gas under a predetermined pressure from the pump; which comprises lowering the temperature of the producer gas to substantially freezing, and at the same time maintaining said gas under a pressure in excess of one atmosphere, passing said cold producer gas through water maintained at a temperature approximately the tem erature of the producer gas to absorb un esirable constitutents from said producer gas, and then admixing the said producer gas and the natural gas. p

`2. The method of diluting natural gas with a gas of lower heat value, such as producer gas, the natural gas being under greater pressure than the producer gas, which comprises expanding the natural gas to operate a pump for compressing the producer gas, with resultant cooling of the natural gas, bringing the expanded natural gas and the compressed producer gas into heat interchanging relation, to etect heating of the one and cooling of the other` and then admixing the two said gases, the natural gas being so expanded and the producer gas'bee ing so compressed, that after the heat interchanging they will be at substantially the same pressure.

3. The method of diluting natural gas with producer gas, the natural gas being under high pressure, which comprises expanding the natural gas to operate alpump for blasting the fuel bed of a producer to cause the generation of producer gas, and for compressing that producer gas to a pressure substantially the same as the pressure oi the expanded natural gas` subjecting the expanded natural gas to heating and the compressed producer gas to cooling to bring them to substantially the same temperature, and then admixing the two said gases.

4. The method of diluting natural gas with producer gas, the Anatural gas being under high pressure, which consists in expanding the natural gas to effecting operation of a pump, with resultant lowering of the temperature of the natural gas, to cause i a blast to be drawn through the fuel hed of a producer to cause the generation of producer gas, to withdraw the generated gas from the producer, to compress the said producer as and to force it under suitable ressure through delivery pipes, and admixing said producer gas with the natural gas, the expanded natural gas and the compressed producer gas being brought into heat interchanging relation with each other before admixture. e

5. The method of diluting natural gas with a low heat value gas, such as'producer gas, the natural gas being under high pressure, which comprises expanding the natural gas to effect pumping action with resultant lowering of the temperature of the expanding natural gas to withdraw the generated gas from a producer and force it from the pump under predetermined pressure; subjecting the compressed producer gas to cooling action; then passing the compressed producer gas and the expanded natural gas through a heat interchanger to cause further cooling of the producer gas and heating of the natural gas; and then admixng the two gases.

6. The method o diluting natural gas with a low heat value gas, such as producer gas, the natural gas being under high pressure, which comprises expanding the natural gas to cause operation of a pump with resultant lowering of the temperature of the expanding natural gas, said pump being connected to the delivery pipe of a producer to withdraw the generated gas from the producer and force it from the pump under predetermined pressure; subjecting the compressed producer gas to cooling action; then passing the' compressed producer gas and the expanded natural gas through a heat interchanger to cause further cooling of the producer gas and heating of the natural gas; then absorbing undesirable constituents from the cooled roducer gas, and then admixing the pro ucer gas and the natural 115 was.

b 7. The method of diluting natural gas with a low heat value gas, such as producer gas, the natural gas being under high pressure, which consists in expanding the natural gas to cause operation of a pump with resultant lowering of the temperature of the expanding natural gas, said pump being connected to the delivery dpipe of a producer to withdraw the generate gas from the producer and force it fromtthe pump under predetermined' pressure subjectingthe compressed producer gas to cooling actlon; then passing the compressed producer as and the expanded natural gas t rough a eat interchanger to cause further. cooling of the producer gas and heating of the natural gas; passing the cooled producer gas through an absorption tank containing water at a temperature approximating freezlng tempera-` ture and at a pressure of several atmospheres, to cause absorption of the carbon dioxide within saidwater; then admixing the treated producer gas with the natural gas; and aerating the water from the absorption tank to remove the carbon dioxide therefrom, and recirculating said aerated water through said absorption tank.

. 8. A natural gas dilution system comprising a natural gas supply pipe; a gas producer; an engine within stud natural gas supply pipe adapted to erform work while expanding natural gas t erein; a pump operated by said engine, the inlet of said pump being connected to the delivery pipe of the said producer so that during operatlon of the pump it will withdraw as from the producer under suction and elivery such gas under any desired predetermined pressure the outlet pipe of the natural gas engine and the outlet pipe of the pump being connected to a delivery main, to introduce the expanded natural gas and the compressed producer gas into said delivery main.

9. A. natural gas dilution system comprising, in combination, a natural gas supply pipe;` a gas producer; an engme connected to said supply pipe and adapted to expand ing means to a delivery main, for effecting admixture of the two gases.

10. A natural gas dilution system comprising, in combination, a natural gas supply pipe, connected to a source of supply of natural gas under well pressure; a gas producer; an engine connected to said supply pipe and adaptedto expand the natura gas to perform work, with resultant lowering of the tem erature of the natural gas; a pum operate by said engine connected to sai producer to withdraw generated 'gas from the producer under suction-and compress said gas, meansfor cooling-the compressed producer gas; means for effecting heat in terchange between the expanded natural gas and the cooled compressed producer gas; and means for introducing the natural gas and the producer gas from the heat interchang ing means into a. delivery main for admixin the two gases.

In testimony whereof I hereto `aiiix my signature.

HARRY F. SMITH. 

